.gitignore Generator
Build a merged, deduplicated .gitignore from curated language, framework, editor and OS presets.
What is gitignore Generator?
A .gitignore generator that assembles a single file from nineteen curated preset blocks. Selecting Node.js and macOS does not produce two conflicting copies of the same pattern, and each block is headed by a comment so the file stays readable a year later.
How it works
Each preset is an ordered list of gitignore patterns. The merge pass writes the selected blocks in the order you picked them, drops any pattern that a previous block already contributed, and appends your custom lines. The result is then re-parsed and linted: absolute paths, backslashes used as separators, duplicates and negations that git can never reach are reported before you commit the file.
- Paste or fill in the input. Drop in a commit message, a diff, a package.json, a path list or a set of options. The tool reads it locally — nothing is uploaded and no repository is contacted.
- Adjust the rules to match your project. Every linter here takes its convention from a setting you can change: allowed commit types, header length, target branch length, known branch names. Set them once to what your team actually uses.
- Copy the result. Generated files copy straight to the clipboard or download as a real file with the right name (.gitignore, CODEOWNERS, LICENSE, COMMIT_EDITMSG), and Reset returns every field to its default.
Examples
A commit message that fails CI
"Updated(auth): Fixed the expired-token redirect." is rejected by release automation and reported here with the exact reasons: unknown type, capitalised description, past tense and a trailing period.
A .gitignore that only half works
The Checker shows which rule decides a path — and why `!keep.txt` inside an ignored directory never fires, the mistake that sends people to Stack Overflow.
A dependency bump nobody reviewed
The package.json Diff separates added, removed and changed entries per section, so a caret bump of a runtime dependency does not hide inside a lockfile-sized pull request.
A diff pasted from a code review comment
The Diff Viewer understands several `diff --git` blocks, mode-only changes, renames and binary stubs, and calls out a pasted `--stat` summary instead of rendering an empty box.
Common mistakes
Committing a .gitignore without checking it
Rules look right and behave differently: a pattern containing a slash is anchored to the root, a trailing slash means directories only, and a file inside an ignored directory cannot be re-included. Check the paths that matter before you commit the file.
Rewriting published history
A clean commit history is worth having, but amend, rebase and filter-repo change commit hashes. Only rewrite commits that nobody has pulled; after a rewrite, push with --force-with-lease rather than --force.
Treating a generated file as if it were reviewed
These tools produce a starting point, not a decision. Check the licence text against the canonical source, read the security policy before publishing it, and make sure a CODEOWNERS team actually exists — GitHub silently ignores rules whose owner has no write access.
Putting slow checks in a pre-commit hook
A hook that takes 30 seconds gets bypassed with --no-verify within a week, and then it protects nothing. Keep pre-commit to formatting and linting, move type checks and tests to pre-push or CI.
Frequently asked questions
Where does the .gitignore file go?
In the repository root for rules that apply everywhere. A .gitignore in a subdirectory only affects that directory and below, which is a useful way to keep monorepo package rules next to the package.
Does a .gitignore untrack files that are already committed?
No. Git only applies ignore rules to untracked files, so a file that was committed before the rule was added stays tracked until you run git rm --cached on it.
Should I use .gitignore or a global excludes file?
Editor and OS noise (.DS_Store, .idea, Thumbs.db) belongs in a personal global excludes file via git config --global core.excludesFile, so each repo's .gitignore stays about the project itself.